Solidity – Transfer Ether from One Account to Another Using Smart Contract

address.transferethernethereumsolidity

I`m trying to transfer ether from account A to a smart contract and from the smart contract to account B. I wrote some code that approximately works on Remix IDE, but I completely got lost with the msg.value.

pragma solidity ^0.5.11;
contract MyFirstContract
{
    function() external payable { }
        function getBalance() public view returns(uint)
        {
            return address(this).balance;
        }
        
    function send(address payable _To )public payable returns (bool)
    {
     _To.transfer(msg.value);
     return true;
    }
}

This works fine if I insert an input in the value textbox on Remix, as shown in the next image:

Remix IDE value

But I need to transfer ether using my Dapp which based on C#. So, how am I supposed to set the msg.value there? Can I do it using Solidity?

Best Answer

You can not use Solidity. That is solely the language to write smart contracts in. You have (at least) 2 options:

web3.js

If your C# dApp has a browser based frontend you can use the library web3.js. A possible call in your JavaScript code would look something like this:

const receiverAddress=""xxx;
await MyFirstContract.methods.send(reveiverAddress).send({ from: account, value: amountToSendWei });

amountToSendWei is the amount you wanna transfer. The function name "send" might create issues because it is already used within web3.

Nethereum

An open source .NET integration library for Ethereum. I don't have personal experience with this one.

Related Solutions

Solidity – Handling Unimplemented Functions in Contracts

The problem is that totalSupply() implementation is missing. Seems like autogenerated getters do not count. So you need to explicitly create the function.

contract StandardToken is Token {
    uint256 _totalSupply;

    function totalSupply() constant returns (uint256 totalSupply) {
        totalSupply = _totalSupply;
    }
}

[Ethereum] Sending entire contract balance to address

If you are sending the money to a contract, and not an account address, then the recipient contract must have a "fallback" function to be able to receive ETH.

Fallback functions tend to look as follows:

    function() external payable {}

though you can add logic within the fallback function if you wish.

Using recipient.transfer(...) limits the transfer to 2300 gas. This means, if you put complex logic within the fallback function, that would cost more than 2300 gas, the transferal will revert. In this case to transfer the ETH to the contract you must use .call.value(address(this).balance)() instead of .transfer.